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By Mario Alvarez

Drilling with tricone drill bits is widely used in the mining industry with a direct impact on drilling safety and costs, however it can be challenging to implement a new supplier of tricone drill bits, choosing a new model of this accessory due to the normal variations of the rock mass or even due to the acquisition of new and modern drilling equipment for open pit blasting operations. This article identifies the most common mechanisms of failure in productive drill holes of tricone drill bits, both in open-pit coal and metal mines, in two South American countries. It also emphasizes the important issues that must be addressed for the optimization of the performance of these accessories, such as the correct identification of the rock mass, the drilling parameters, and the impact of autonomous drilling on new equipment with this technology. The article presents some of the successful actions to economically improve the performance of drill bits considering the close relationship in the field with the supplier's technical representatives and factory designers, as well as the commercial interrelationship between their respective business areas. The article concludes by discussing the future of tricone drill bit design development, its environmental management, and possible new advances in its manufacture.

Jan 21, 2025

By Cang Daqiang, Li Yu, Liu Xiaoming, Zong Yanbin

"Utilization of high-quality heat in melting slag is a great challenge for iron and steel industry. In the paper, a new method is put forward to concurrently utilize heat and slag by converting the melting slag directly into high valued materials, slag glass-ceramic. A glassceramic with a higher basicity of 0.7 than traditional basicity of 0.45 was prepared from steelmaking slag in order to utilize more hot melting slag. Effects of Alz03 on its crystallization processes were researched by XRF, DTA, XRD and SEM. Results show that Alz03 in glassceramic would have great effected on its property. When the Alz03 content ranges within 12%-15%, glass-ceramics with basicity of0.7 could reach the best performances. The change of dominant phase in glass ceramics from akermanite and wollastonite to akermanite and gehlenite would significantly degrade its mechanical property. An increase of Al2O3 content leads to a rise of the viscosity and crystallization activation energy of the glass, while results in increasing sintering temperature and crystallization temperature of glass, which contributed to its fully crystallization and densification process.IntroductionSteel slag is a by-product under a process of converting iron to steel at above 1600°C, and 0.1-0.15 ton molten steel slag would be discharged for producing per ton of steel in the process. The discharged steel slag at 1600°C has heat of 68 kgce/t. In 2012, China's steel output reached 716 million tons, and produces about 100 million tons of steel slag and 68,000 tee of heat in it [1,2]. But at present, utilization of both slag and its heat at 1600°C is a great challenge for iron and steel industry.Dry granulation of melting steel slag by air and then recovering the heat of the hot air are a traditional technology which have not yet been put into practice for very low heat conductivity of the slag and low efficient of heat exchange among the different processes [3,4]. Therefore, a new method for high efficient utilization of both steel slag and its high temperature sensible heat is put forward [5,6], which is on-line reducing and extracting iron from molten steel slag and then directly preparing glass-ceramic by use of the residual molten slag."

Jan 1, 2014

By Charles W. Goodale

In the course of the preparation of my paper on " The Occurrence and Treatment of the Argentiferous Manganese Ores of Tombstone District, Arizona" (Dam., xvii., 767), my attention was called to two patents which have been issued for the use of a diaphragm at the upper end of a Howell furnace, whose importance merits more than a passing reference. Mr. J. K. Pardee invented and first put into use in the Algon quin mill, at Philipsburg, Mon., in 1880, a ('new' and useful im provement in rotary ore-roasting furnaces," which was intended "to increase the capacity, effectiveness and working economies of such furnaces." The following description and accompanying figures are taken from the patent papers, dated December 21st, 1880: Fig. 1 is a side elevation of the feed-end of the Howell rotary furnace, with parts broken away, the better to exhibit my invention. Fig. 2 is an end elevation of the same. Fig. 3 is an end elevation of the same, showing a modification of my invention. In operating a furnace of this kind, of the capacity of one ton of ore an hour, it was found that for the best work the two fire-places (one at each end of the revolv ing cylinder) consumed about ten cords of wood every twenty-four hours, and that about twenty-fonr tons of silver-ore were introduced through the feed-pipe. It was also found that of the amount of ore, fully one-third did not go through the revolv ing cylinder, but went into the dust-chanibers about the feed-end of the furnace or cylinder, and this ore going into the dust-chambers was found not to be sufficiently chloridized for amalgamation, but had to be re-roasted. I then caused to be made, out of boiler-plate iron, a segment of a circle, the height of which was about one third of the diameter of. the cylinder or furnace, the circumference of the circle being smaller than the circumference of the furnace, so that about a half-inch space would be left between the plate and the furnace, when said plate or segment was in position. This segment or plate of iron was then fastened to the bottom of the feed pipe, as shown in the drawings, wherein A represents the revolving cylinder or furnace; B, the fire-place and dust-chambers at the feed-end of said furnace; C, the inclined feed-pipe, and D, the diaphragm, partition, or plate fixed within said furnace, A. With the diaphragm or plate, D, in the position shown, the furnace was run for about a month, and it was found that with the furnace in best working condition only four cords of wood every twenty-four hours were consumed, that no fire was required at the feed-end of the furnace, that not one-twelfth of the ore

Jan 1, 1890

By Paul T. Alexander

After evaluating preceding studies and designs of lightweight supports, ESD selected the all-hydraulic and the hydromechanical concepts for detailed design and fabrication. Further analysis and testing showed that the all-hydraulic design was economically justified and met all the crucial engineering, manufacturing, and design criteria identified during the evaluation phase. Following Bureau of Mines approval of the detailed design, four all-hydraulic support models were fabricated. Once functional and structural testing was successfully completed, 40 additional units were constructed and distributed for in-mine testing. The units were very well-liked by all three demonstration mines. The wide- spread interest in supports for seam heights greater than 8 feet led to expansion of the design data package. ESD designed four basic models to cover the new height range, but no hardware has yet been fabricated for the new design.

Jan 1, 1982

By Peter Ay, Vincenz Mehlstaubl, Satyanarayana Narra

"This study gives an insight into non-destructive testing methods suitable for porosity analysis at a small scale, firstly summarizing relevant state-of-the-art technology and pending patents, secondly realizing and documenting the start-up of the VHX-2000 digital microscope by the manufacturer Keyence and thirdly demonstrating practical application with the extended analysis of three fundamentally different agglomerates for which important application-related parameters are determined. Various analysis procedures on the different agglomerates the efficient and timesaving operational features of the digital microscope are outlined. Firstly an analysis of flax fibre agglomerates determines the process conditions best suited to produce agglomerates with specific properties by determining sphericity, cubicity, density and porosity as well as fibre damage and alteration. Secondly the production of iron-hydroxide - hemp-fibre agglomerates serves to obtain information on porosity values as a result of a cauterization of the fibres. The third analysis provides estimations of porosity values for acid-treated lignin agglomerates. Measurements were carried out with compact dry agglomerates and with soaked, expanded agglomerates, determining factors for total water carrying capacity. Practicability of non-destructive testing by digital microscopy is demonstrated and explained concerning the applications in this study by obtaining definite structural findings about the analysed agglomerates. Information on its operation is made available by a practice-oriented manual for the VHX-2000 digital microscope. Further suggestions for more in-detail analysis results with different instruments are given."

Jan 1, 2014

By Thomas A. Edison

We have not yet begun. to realize the possibilities of automatic machinery, in part because we have not developed the designing brains, and in part because we have not sufficiently simplified industry to make possible the economical use of such machinery. The principle of the Jacquard loom, has scarcely been utilized except in weaving silk and in the player piano. It is the principle of bringing into action the various parts of a machine in accordance with a pattern traced on a steel card by perforations or as on the paper roll of a player piano. This principle gives us a control which can be applied to any kind of machine. It is a' great reserve principle for the future. But even now, with the machinery that we have at command, anyone can cut the number of employees in two, at the same time doubling his output, by installing semi-automatic or automatic machinery. And no one knows how far this process can go on. Cutting down the number of men is not just putting some poor fellows out of a job. It is increasing the number of good jobs by increasing the production per capita to a point where really satisfactory wages can be paid out of it, and this in turn- increases the amount of work required to be done and creates new jobs. Thus, cheapening in- creases the demand.

Jan 1, 1929

By Daniel Harrington

On the night of June 8, 1917, the flame of a carbide lamp accidentally set fire to the uncovered and frayed insulation of an armored power cable near the 2,400-foot level of the North Butte Mining CO.'s Granite Mountain shaft. How this, insulation accidentally became exposed is explained on page 15. The highly flammable oiled fabric set fire to the shaft timbers, and as this is a downcast shaft the fire spread with great rapidity, soon filling the mine workings with smoke and gas. At the time 410 men were working underground, 247 of whom escaped by various means, but most of the 163 remaining were probably overcome soon after the fire started, and perished. Only two men were actually burned. The cause of the disaster was purely accidental. The immediate effect was the unexpected reversal of normal conditions; the ultimate effect was great loss of life and the destruction of the main hoisting shaft, putting it temporarily out of service. The work of rescue and fire fighting continued eight days. The following pages present an attempt to draw some practical conclusions and suggestions from this disaster. The property of the North Butte Mining Co. consists of about 220 acres in the northeastern part of the Butte district, Montana. Next to the Anaconda Copper Mining Co. it is the largest producer of the district. In 1916, the year before the disaster, there were 1,160 men employed. The output was 560,947 tons of ore, which yielded 24,498,181 pounds of copper, 1,047,063 ounces of silver, 1,712 ounces of gold, and 412,953 pounds of zinc. The profit was $2,479,595. The total development work for that year was 21,694 feet. During the first half of 1917, the year of the accident, the daily tonnage of ore averaged 2,000, an increase of 400 tons over that of the year 1916.

Jan 1, 1922

By R. A. (Dick) McIvor

"It is important to ensure that the basic mine hoist plant design fundamentals are incorporated into any new mine hoist plant project before detailed design engineering is commenced. Some of the basic design fundamentals to be considered are: hoist rope fleet and flight angles for good hoist rope coiling, hoist rope harmonic frequency study to ensure that the hoist rope does not run at full speed at a rope resonance frequency, head frame and shaft clearance diagrams to establish the optimum positions for the loading and dumping of the shaft conveyances, access in the head frame and shaft collar for hoist rope and shaft conveyance installation and removal. Failure to consider the hoist plant fundamentals before detailed engineering commences will result in extra costs for hoist plant redesign or a significant increase in operating and maintenance costs for the mine due to increased hoist plant downtime to perform tasks and a lower mine operating efficiency. INTRODUCTION The mine hoisting plant is the most critical single line component in the operation of a shaft sinking operation or a permanent installation. Bad decisions in the design and selection of the hoist plant equipment can significantly add to the operating costs and up-time in the operation of the mine. Mine hoisting plant equipment installed costs represent approximately 5 to 8 percent of the capital cost of a new mine, yet price sometimes becomes the deciding factor for procuring the hoist plant components, sometimes selecting used equipment that may compromise the design and maintainability of the mine hoist plant. Mine downtime can cost upwards of $100,000 per hour and it will not take a very long time to eat up all the so-called savings on hoist plant equipment purchases. This paper will provide guidelines for the design, selection, installation and maintenance of mine hoist plant equipment with the objective to having the right mine hoist plant with the highest operational availability and best maintainability. PRELIMINARY DESIGN INFORMATION Before any engineering commences, the following information needs to be obtained to allow the preliminary sizing of the hoist plant equipment: • Shaft depth: The shaft depth will influence the hoist rope selection based on the material and personnel loads anticipated for the mine design. The shaft depth will also influence the maximum speed of the shaft conveyances. • Annual production: The desired annual production will influence the required payload sizing with allowances for maintenance and inspections of the hoist plant equipment."

Jan 1, 2019

By Gilman Y. Murray

The problems connected with the development of economically acceptable water supplies in arid regions are discussed. The techniques for capture and retention of runoff from infrequent desert storms are described and the major factors involved are emphasized. The exploration and planning for a typical water development in southwest United States is described, including an analysis of capital and operating costs for the proposed system.

Jan 1, 1963

By M. Askari, A. Ahmadi

"This study was conducted to establish the possible application of bioleaching in the pilot scale to recover valuable metals from the sulfidic tailings of Golgohar Iron Mine (Kerman, Iran). Using bioleaching processes, solvent extraction and sulfide precipitation recovery of valuable metals including, copper, cobalt and nickel from the tailing was investigated. The results showed that the optimum pH and temperature conditions relative to the bioleaching step was 1.5 and 45°C. The extraction of the metals from the low grade polymetal resource with complex mineralogy is very important from economic, environmental and technical point of views. Moreover, the proposed method has some advantages from energy saving, tailing management and creating added value from waste materials aspects.INTRODUCTION The growing demand for base metals and strategic such as: copper, nickel and cobalt as well as high-grade resource depletion has caused them, the mining industry to extract metals from low-grade resources and driven by complex mineralogy (Xie et al., 2005). Economic extraction of metals with low grade sources requires low-cost and efficient processing methods. A source with enormous potential for metals in future, secondary sources, such as: tailings mineral industries which the lack of appropriate technology and the high cost of processing weren't recoverable with previous procedures in the past. But it is possible that with develop new and efficient technologies have the economic exploitation ability. Recovery of metals from tailings resources is very important not only in terms of precious metals but also in terms of reducing environmental problems (due to heavy metals). The metals of copper, nickel and cobalt are mainly like sulfide compounds in the nature, usually for their recovery, first they make ore with flotation method to obtain the sulfide concentrate that containing valuable metals. then for the metal production, it will be melt and purification. Due to the environmental aspects, technical problems in the recovery of base metals from low grade ore and mixes, the presence of small reserves, in the past three decades they pay much attention to the use of hydrometallurgical processes for the recovery of base metals from these resources. These processes are classified according to the solver agent to leaching sulfates, chlorides, nitrates and amines (Hackl, 1995). Early, chloride leaching under oxidation condition in acidic or alkaline solutions was recognized the best process to produce sulfide concentrates. But then the basic processes sulfates was considered as the superior process because of being easier, a better understanding of the chemistry of leaching and recovery of base metals, especially copper from the environment easier sulfate solution with an organic solvent extraction and electro winning. The bioleaching is shown its ability on a commercial scale of low-grade sulfide minerals and ore that because of environmental reasons, the possibility of melting is not possible to them. The existing industrial base factories are based on primarily on the bioleaching and pressure leaching and recovery of cathode copper sulfate solution by extraction with organic solvents (SX) and electrowinning (EW) (Wang, 2005). Preliminary analysis has shown that valuable elements such as copper, nickel and cobalt are in the float flotation unit. Hence the plan to extract these metals from the wet tailing stream has been done."

Jan 1, 2017

By J. Sehata, J. Tshilongo, I. Govender, S. Pikinini, T. L. Moodley, M. Raedani

In the face of dwindling Merensky ore reserves in the early 1990s, Mintek developed the MF2 flotation circuit to economically recover platinum group metals from the shallow upper group-2 chromitite reef. By aligning the primary and secondary grind to the platinum group metal liberation kinetics, excessive fine chromite generation was avoided, and thus one could consistently produce high-grade concentrates (>200 g/t platinum group metals) with low chrome content (<3% Cr2O₃), well within smelter tolerances. This, coupled with upper group- 2's low-cost open-pit mining, made it particularly attractive to investors and mining houses alike. As a result, deeper lying reefs like middle group and lower group with lower platinum group metals grades and complex mineralogy, were primarily mined only for chromite using density-based separation processes (like spirals), of which the waste tailings are best classified as secondary platinum group metals resources. Today, with global platinum group metal demand rising and high grade upper ground-2 reserves rapidly diminishing, the industry must revisit these middle group and lower group tailings. Mineralogical analysis reveals several challenges: Middle group tailings feature platinum group metals locked within silicate matrices, while lower group tailings contain fine chromitite fragments, and are hosted within non-floating laurite grains, each presenting liberation and gangue issues. Smelter constraints still demand concentrates below 3% Cr₂O₃, requiring solutions that consider both platinum group metals recovery and chrome entrainment. To develop a solution, two lower group chrome spiral tailings samples were obtained from a large chrome mine: Sample A (+425 μm – 106 μm) and Sample B (−106 μm). Initial assays showed Sample B contained higher platinum group metal grades but also higher Cr₂O₃. As such, different blends of flotation feeds were evaluated using ratios of 90:10 (C1) and 80:20 (C2) of Sample A to Sample B, targeting the coarse fraction's lower chrome content while recovering valuable platinum group metals from the fines. This work proposes a practical route for mining houses to unlock additional platinum group metal value from lower group ore spiral tailings. By optimising blending ratios and reagent suites, it is possible to meet smelter chrome and platinum group metal grade thresholds, whilst still obtaining economically viable PGM recoveries.

Mar 6, 2026

By A. Flora, E. Bilotta, F. Foria, V. Nappa

"All the typical applications of deep mixing rely on the good mechanical properties of the improved columns to strengthen or stiffen the ground for a number of geotechnical applications.This paper focuses on a completely different kind of deep mixing, carried out in order to obtain columns much softer than the surrounding soil. This kind of deep mixing, named Soft Deep Mixing (SDM), is introduced as an original means to tackle seismic risk, and can be convenient when the existing structure to be protected has a historic relevance that cannot be altered with structural modifications. The idea is that properly assembled layers made of partially overlapped SDM columns, with dynamic impedance much smaller than that of the surrounding soil, will filter and reflect most of the seismic energy.The paper presents the results of some 2D parametric numerical analyses aimed to investigate the seismic performance of this innovative approach. Simplified dynamic inputs (Ricker wavelets, having only one largely predominant frequency) were adopted to better understand the effect of signal frequency. The analyses show that the effectiveness of the soft grouted isolating barrier depends on soil and SDM geometrical, physical and mechanical properties, as well as on the frequency content of the seismic input.INTRODUCTIONPassive structural systems installed at the foundation level of existing buildings are a common solution to protect them against earthquakes. However, installation procedures are expensive and not always feasible, as for instance in the case of valuable buildings. As an alternative, ground improvement techniques can be used to modify ground properties, in order to mitigate the intensity of shaking at ground level. The propagation of shear waves in the ground can be modified by introducing a layer of artificially modified material, having a dynamic impedance (defined as n =p VS, where p is the material density and VS the velocity of shear waves) very different from that of the natural soil. Both very high or very low values of the dynamic impedance of the grouted soil (nt) can be effective in reducing the overall transmitted energy, with the difference that – for a given reduction of the transmitted energy - stiff grouted layers tend to filter the low frequency components of the amplitude spectrum without modifying in a significant way the high frequency components, while soft grouted layers have the opposite effect. Then, ideally the choice of the best grouting technique should be made considering the effects of the different frequency components on the building to be protected. These effects are detrimental for the structure when they are close to its natural frequency: high frequency components result into large structural loads on massive squat structures (high natural frequency), and low frequency components may be critical for tall and flexible structures (low natural frequency). Therefore, the typical procedure of stiffening the uppermost soil layers regardless of the kind of building to be protected is not necessarily beneficial, and for the case of squat structures soft grouting should be preferred. However, this procedure has not been taken into account yet in the engineering practice, and may pose static problems at ground level (i.e. excessive static settlements)."

Jan 1, 2015

By C. N. Eze, C. K. Ezeh, O. Nnabuife, N. M. Ugwoju, S. C. Enemuor, V. Okechukwu

In this study, the efficacy of Providencia vermicola KUBT-1 in the leaching and beneficiation of Agbaja iron ore was evaluated under varying conditions of temperature, ore particle size, and pH. Agbaja iron ore is a Nigerian low-grade ore containing about 43%–52% iron and a high amount of gangue materials, including phosphorus (1.4%–2.0%) and sulphur (0.12%). The study was organised in triplicate in shake flasks with 48 samples. One millilitre of washed cells of Providencia vermicola KUBT-1 suspended in normal saline at 0.5 McFarland standard (108 cells ml-1) was introduced into each flask containing 50 g of sterilised ore in 100 ml of bioleaching medium, and the samples incubated at room temperature for eight weeks. The levels of upgraded iron, mobilised sulphur, and phosphorus were determined by atomic absorption and ultraviolet spectrophotometric analyses, respectively. Results showed that a particle size of 0.8 mm was optimal for iron upgrading and sulphur mobilisation while 1.0 mm ore size was optimal for phosphorus mobilisation. Up to 89.60% of the iron was upgraded while phosphorus and sulphur were mobilised, leaving residual values of 0.223% and 0.02%, in the ore, respectively. The organism produced best beneficiation results at a pH of 2.5 and a temperature of 3ºC. Correlation analysis with the Pearson’s correlation model showed a positive correlation between iron upgrading and sulphur-phosphorus removal (r =1.000, and r =0.967), respectively. These results present Providencia vermicola KUBT-1 as a promising candidate for large scale leaching and beneficiation of Agbaja iron ore.

Dec 15, 2025

By Frank B. Fulkerson

Of the about 60 million pounds of aluminum used in the Pacific Northwest in 1960, 40 million pounds or two-thirds was used by 10 companies. One of these companies made airplanes and missiles; one manufactured roofing, siding, and tubing; three produced truck tractors, truck bodies, or truck trailers; two made architectural metal products; one made irrigation and industrial products; one was a general foundry; and one was a shipyard. These companies contributed to regional growth by developing markets outside the area; some have worldwide sales. Aluminum consumption increased at an average rate of 7 percent annually from 1954 to 1960. Airplane manufacture, formerly preeminent in aluminum use, no longer was in first place in 1960. By industrial group, the leading users were manufacturers of building products, 30 percent; airplanes and missiles, 22 percent; truck tractors, truck bodies, and truck trailers; 17 percent; general foundries, 5 percent; ships and boats, 4 percent; mobile homes, 4 percent; other transportation equipment, 3 percent; and irrigation equipment and all other products, 15 percent.

Jan 1, 1962

By R. W. Brigstocke

History The birth of the mining industry of Canada took place about 1670. According to Salone (Salone E., La Colonisation de la Nouvelle France, page 205) the first discovery of ore in the country was made by an iron-master, Monsieur de la Potardiere, near Trois Rivieres, Quebec. Under French rule some prospecting was done; but at this time no one seemed to consider the working of mines practicable. It was not until the time that Begon became Intendant, when the Marquis of Vaudreuil was Governor, that mining was attempted. Begon was a patron of industrial arts and did his best to promote home manufactures. The mining industry was developed under his regime and discoveries of copper and lead ores were made in 1730. About this time the St. Maurice Forges were erected to treat bog-iron ore, and they were in operation for many years. Prior to 1747, iron pans to the value of £21,000 were manufactured, together with bar-iron and plough-shares. About 1769, that is, ten years after the conquest by Wolfe, stoves and other articles, and, later, potash kettles, appeared. What is still more interesting to us-or was, at least, to General Wolfe-is that cannon balls made at the St. Maurice Forges delayed his operations. A map dated 1744, a copy of which appears in the report of the Ontario Bureau of Mines for 1913 (Vol. XIX), indicates the extensiveness of the wanderings of the French and also shows the location of the lead mine on the east shore of Lake Timiskaming. Bog-iron ore was turned into metal, with charcoal for fuel, at Norman-dale, Norfolk county, Ontario, in 1813, and at Clementsport, Nova Scotia, in 1825. In a volume published in 1672, reference is made to the occurrence of coal on the Atlantic seaboard, and in 1677 Monsieur Duchesneau, the Intendant, levied a royalty of twenty sous per ton on all coal taken from Cape Breton.

Jan 1, 1932

By Brian R. Castle, James J. Scott

INTRODUCTION Referring to a ground support system as a &apos;band-aid&apos; borders on getting cute, but the application of cable slings in U.S. mining is somewhat analogous. Where problems in the roof or rib require additional support, the versatile cable sling is the answer in a variety of conditions. To fully understand how and why cable slings are used today we must briefly review their development history. Much of the thrust over the last five to seven years in ground support fixtures has been the development of hybrid systems. Taking the best of two or more existing roof bolt fixtures and marrying them into a new fixture which exhibits the good characteristics without the bad of the parent systems. Resin point anchored mechanical bolts, continuous threaded rebar bolts, and others have all be- come important fixtures in rock mass stabilization. HYBRID GROUND SUPPORT SYSTEM The cable sling system is also a hybrid, both in its parentage and in its ground support characteristics. See figure 1. Cable slings combine the techniques of cement. grouting high-strength cables, Friction Rock Stabilizers, and truss-like suspension into a versatile and high- strength ground support system. 1/2" high-strength cable is cement grouted in place in a manner similar to pre-

Jan 1, 1983

In recent years, coal beneficiation has gotten considerable attention. Selective oil agglomeration has been accepted as the best method to produce clean coal with a high removal of pyrite sulphur. In this study, spherical oil agglomeration of Datong coal fines was carried out using diesel oil as a bridging liquid. The oil agglomeration has a surface properties based on coal cleaning technique. The effects of fundamental parameters have been investigated including the concentration of bridging liquid, the size of coal particle, the solid content of slurry, the agitation time and rate, pH, surfactants on the agglomeration performance and various salts on the ash rejection and removal of pyrite of the agglomerated products. The optimum conditions of particle size, diesel concentration, solid content, agitation speed and time, pH and the dosage of active agent have been determined as less than 8µm, 20wt%, 1200r/min and 10 minutes, 7.5g/t and 100g/t, respectively. Under these conditions the ash content in the products can be achieved 1.5% below, the ash rejection was up to 92%. It has been observed that ionic strength of the aqueous medium affects the agglomeration performance. The precombustion coal cleaning process based on improved selective agglomeration results in high ash and pyrite sulphur removals. Over 80% removal of pyrite sulphur can be achieved from run-of-mine coals by offering a more cost-effective sulphur reduction solution rather than any other SO2 removal technology. In addition, the removal of pyrite sulphur is very necessary for not only the prevention of environmental pollution but also economical reasons.

Jan 1, 2014

By Thomas B. Douglas

INSTRUMENTATION in the process industries can no longer be regarded as a convenience, but rather an absolute necessity. Although many chemical processes must already be conducted with instruments, every properly designed application of automatic process control will improve operation: 1) the product will be more uniform and of higher quality; 2) the manual labor saved will reduce cost; 3) uniformity of flow and uniform control of process will increase production; and 4) surges will be eliminated, making it possible to operate equipment near ultimate capacity at all times. Industrial instruments fall into two general classifications-those that measure and those that measure and control. The cement industry has been using instruments for a number of years, particularly in the burning process, primarily for indicating and recording. Automatic process control makes additional use of these instruments, and others, to control variables. Assisted by the instrument manufacturers, engineers at Ideal Cement CO. achieved considerable progress in determining how well the usual recording instruments could be made to control various phases of cement-making. The results of these experiments were used to make the new plant at Houston as wholly automatic as possible.

Jan 2, 1958

By A D. Campbell, G R. Power

The increasing availability of marker data in sublevel caving operations is changing the way draw can be managed to achieve positive recovery outcomes in these mines. This paper describes how marker data has been incorporated into flow simulations to help calibrate full mine ore recovery simulations for the forecasting and optimisation of recovery.Some flow modelling techniques do not use marker data, relying instead on the outcomes of physical and numerical experiments to guide assumptions about an idealised recovery flow shape. Other mines have access to marker trial data, but find it difficult to specifically link this marker trial information to their recovery models. This can make it difficult to create a link between the marker trial information and recovery forecasting and limits the potential value of the marker trials at the mine.In the simulations shown here, the marker rings are fully incorporated into the flow model, and can be tracked in the model. The model is compared against the real underground marker recovery information to give the user an indication of how accurately the flow settings in the model are reflecting the conditions in the experimental marker rings. An example of use of this system at an operational mine is included.CITATION:Power, G R and Campbell, A D, 2016. Modelling of real-time marker data to improve operational recovery in sublevel caving mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 105–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By I. Ashmole

The dimension stone industry is not widely known or appreciated within the mainstream mining industry. This is in spite of the fact that the industry has grown at an average of over 7% per annum since 1980, and is estimated to now have a global turnover in excess of US$ 60 Billion per annum. Production technologies, particularly in the developed world where labour costs are high, have developed rapidly over the past two decades. Aligned with this, there has been a significant trend in adoption of a more professional mining approach in the exploration for and operation of dimension stone quarries. In fact, in the experience of the authors, mining a dimension stone deposit successfully if often more challenging from a mining engineering point of view than many conventional surface mines. This paper gives an overview of the industry and then proceeds to discuss best practice in exploration for dimension stone and to outline the latest technologies applied in mining of dimension stone. These technologies are varied and the specific combination of technologies applied in any given quarry is determined by both the physical properties of the material as well as the influence of geology which significantly impacts on the recovery of saleable material and hence the economics of the quarry.

Jan 1, 2008